The invention is directed to a roller chain particularly for bicycles with derailleur. The chain comprises alternately arranged inner and outer links which are connected with one another in an articulated manner, wherein the outer links comprise a pair of outer plates which are connected with one another by means of two pins, and the inner links comprise an inner plate pair which is arranged between the outer plates and supported on the pins so as to be rotatable. Two tubular elements (bearing collars) are arranged at the inner plates, which tubular elements carry a roller and comprise the pins in each instance.
A variety of such chains are known. Thus, e.g. D. J. Mackintosh in U.S. Pat. No. 2,568,649 shows a roller chain with a bearing collar drawn out of the inner plate. Sedis DE 28 29 424 likewise shows different versions with the bearing collars drawn out of the inner plate. These collars are cylindrical with respect to their outer and inner diameters and are applied to the center of the pin. In order to obtain a good pressing of the link between the pin and collar, exacting tolerances are prescribed which correspond to a running clearance between the pin and collar of a maximum of approximately 0.05-0.1 in commercially available high-performance chains. Accordingly, the pins can swivel by, at most, approximately one degree into the bearing collar in completely assembled brand-new chains, so that the chain has very little flexibility in the lateral direction.
An increase in the movability of the pin would be possible only by means of a greater running clearance; but this would have disadvantageous results for the pressing of the links due to the difference between the radii of the pins and bearing collars. Moreover, an increase in the running clearance allows a greater rotation of the links around the longitudinal axis of the chain, which becomes noticeable in a very negative manner during the shifting process.
Further, in the known roller chains, the running clearance between the pin and bearing collar and between the bearing collar and roller which is required for technical reasons relating to manufacture and operation results in increased elastic deformations of the articulated structural component parts at high load transmission due to the high pressing of the links. It makes itself felt chiefly in an elastic lengthening of the chain in the order of magnitude of three to five hundredths of a millimeter per chain link in that area of the meshing of the teeth in which the load is transmitted to the chain gear wheels, wherein this lengthening acts chiefly between adjacent inner links.
In addition to the elastic lengthening of the plates themselves, this is a substantial reason why the chain links slide up on the tooth flanks of the loaded teeth of the chain wheels and is accordingly a substantial cause of wear of the tooth flanks. Since the link wear in conventional chains also makes itself felt in a lengthening of the chain between adjacent inner links, these negative factors accumulate.